1. Field of the Invention
The present invention relates to fall restraint systems, and more particularly, to fall restraint systems for telescoping ladders.
2. Description of the Related Art
Firefighters are rescuers extensively trained primarily to extinguish hazardous fires that threaten civilian populations and property, and to rescue people from dangerous incidents, such as collapsed and burning buildings. The increasing complexity of modern industrialized life with an increase in the scale of hazards has created an increase in the skills needed in firefighting technology and a broadening of the firefighter-rescuer's remit. They sometimes provide emergency medical services. The fire service, or fire and rescue service, also known in some countries as the fire brigade or fire department, is one of the main emergency services.
In many cases, firefighters require telescoping ladders including turntable ladders, tower ladders, tiller ladders, quint ladders, quad ladders, and/or ladders that mount onto hydraulic platforms while performing fire service, and/or fire and rescue services. Preventing injuries from a slip or fall, especially while ascending or descending the telescoping ladders is always desirable.
Applicant believes that one of the closest references corresponds to U.S. Patent Application Publication No. 20100326768 A1, published on Dec. 30, 2010 to Kerstetter, J R. for a fall-arrest ladder system. However, it differs from the present invention because Kerstetter, J R. teaches a safety-featured ladder, including taut rope wrapped over top of the top rung and under bottom of the bottom rung and fixedly connected to the ladder when downward force is applied to the rope in front of the ladder. In a first embodiment, a sleeve including a pulley subsystem is attached to a body harness worn by a climber and can move or slide along the rope only when climbing up ladder. In a second embodiment, a sleeve including a different pulley subsystem including a centrifugal brake is attached to a body harness worn by a climber and can move or slide along the rope when climbing up or climbing down. However, if the climber loses footing and starts to fall the sleeve grabs the rope, and/or the rope grabs the sleeve, which prevents the climber from falling more than a few inches and from injury. Hooks at top of the ladder can hook around transverse cables atop poles.
Applicant believes that another reference corresponds to U.S. Patent Application Publication No. 20100219016 A1, published on Sep. 2, 2010 to Meillet for a fall arrest assembly. However, it differs from the present invention because Meillet teaches a fall arrest assembly that includes a rotational drum, at least one pawl and a catch. The rotational drum is configured to rotate in response to a movement of a lifeline. The least one pawl is in rotational communication with the rotational drum. The at least one pawl is further configured to pivot about a pivot connection in response to select rotational velocities of the rotational drum. The at least one pawl is also configured to engage the catch when the at least one pawl pivots in response to the select rotational velocities of the rotational drum to stop the rotation of the rotational drum and movement of the lifeline. An elastic bushing for each pivot connection is also used. Each elastic bushing is positioned about an associated pivot connection of an associated pawl. The elastic bushings deform in shape as an associated pawl engages the at least one portion of the catch.
Applicant believes that another reference corresponds to U.S. Patent Application Publication No. 20020014370 A1, published on Feb. 7, 2002 to Casebolt, et al. for a fall arrest methods and apparatus with u-joint connector. However, it differs from the present invention because Casebolt, et al. teach a fall arrest device that includes a housing, a braking assembly, and a coupling assembly. The braking assembly cooperates with an elongate support to facilitate controlled movement of the fall arrest device along the elongate support. The coupling assembly is interconnected between the housing and a person to be supported by the device in the event of a fall. The coupling assembly includes a universal joint to accommodate various connection arrangements between the fall arrest device and the person.
Applicant believes that another reference corresponds to U.S. Pat. No. 6,804,830 B1 issued to Reynolds, et al. on Oct. 19, 2004 for a full body harness for fall arrest. However, it differs from the present invention because Reynolds, et al. teach a full body harness, which can include curved webbing, a spreading back pad and/or leg buckles which improve the comfort, use and performance of the harness. Preferably, the harness uses five pieces of webbing, namely, two curved webbing shoulder straps, two identical leg straps, and a subpelvic strap. The harness can also have a spreading back pad, which helps to keep the shoulder straps from riding up onto the neck of the wearer.
Applicant believes that another reference corresponds to U.S. Pat. No. 6,260,662 B1 issued to Meister, et al. on Jul. 17, 2001 for a retractable extension for the guiding rail of a climbing guard. However, it differs from the present invention because Meister, et al. teach a device for allowing a person to safely step off from and onto a climbing track on a roof edge, a roof slope, a shaft opening or similar, that includes a guide rail (10) for guiding a catching device to which a person using the climbing path can be secured, and an extension piece (24) of the guide rail (10). The extension piece (24) of the guide rail (10) can be moved between a first and a second position, the extension piece (24) being so arranged in the first position that it does not project above the guide rail (10), and being aligned in longitudinal direction with the guide rail in the second position. The extension piece (24) can be guided displaceable along the guide rail (10) and at a distance from the latter and can be swiveled by 180 degree in the final position, which corresponds to the second position, so that it is in alignment with the extension (10).
Applicant believes that another reference corresponds to U.S. Pat. No. 6,161,647 B1 issued to Braden, et al. on Dec. 19, 2000 for a fall arresting ladder safety device. However, it differs from the present invention because Braden, et al. teach a fall arresting ladder safety device for attachment to a fixed ladder side rail. The fall arresting device is to be used in conjunction with a body harness worn by the climber with a lanyard attached at one end to the body harness and the other end attached to the fall arresting device. The fall arresting device includes first and second arms pivotally connected in an X-configuration with each arm having first and second ladder side rail engaging portions disposed on opposite edges of the ladder side rail. A spring operably attached to the first and second arms biases the first and second arms between a fall arresting position and a climbing position. To ascend or descend the ladder, the handle portion of the first arm is pivoted upward to disengage the ladder side rail engaging portions of the first arm so that the device can be rolled up or down the ladder side rail as the ascends or descends the ladder. The arms of the fall arresting device can be locked into a disengaging position such that the fall arresting device can be removed from the ladder side rail and carried by the climber for later use when descending the ladder or ascending another ladder.
Applicant believes that another reference corresponds to U.S. Pat. No. 5,265,696 B1 issued to Casebolt on Nov. 30, 1993 for a ladder climbing safety clamp. However, it differs from the present invention because Casebolt teaches a ladder climbing safety clamp that may be easily operated by a worker with one hand while overcoming many potential safety hazards of prior devices. The safety clamp includes a body with a U-shaped cable sleeve. A channel is included on one side of the body to permit the introduction of the safety line in the cable sleeve. However, if the cable is too large to operate properly with the safety clamp, it will not fit through the channel, thereby helping to prevent inadvertent usage of the safety clamp with a cable of a diameter for which it is not intended. A gravity stop prevents the safety clamp from being inadvertently installed in an upside-down position, since the safety clamp would not operate correctly in that position.
Applicant believes that another reference corresponds to U.S. Pat. No. 5,161,639 B1 issued to Ice on Nov. 10, 1992 for a derrick counterweight assembly. However, it differs from the present invention because Ice teaches an assembly that has a safety line, which is attached to a harness, which secures to a worker to be used while climbing the ladder of the derrick. Telescoping tube sections are mounted to the derrick for extension and contraction with the derrick sections. The line is trained over a pulley attached to the crown of a derrick, and then passes into the telescoping tube. The line is connected to a counterweight located in the telescoping tube. The line and counterweight remain inside the telescoping tube during rig up and rig down of the derrick.
Applicant believes that another reference corresponds to U.S. Pat. No. 4,458,781 B1 issued to Ellis, et al. on Jul. 10, 1984 for a climbing aid and safety descent device. However, it differs from the present invention because Ellis, et al. teach a controlled descent device, which aids in the ascent of a human being from a lower elevation to an upper elevation and provides for the safe descent of a human being from the upper level to the lower level. The apparatus comprises a round cable, a counterweight, a controlled descent pulley having a ratchet and pawl brake system and a conventional pulley; all operating conjunctly dependently on the position and situation of the human being. The controlled descent pulley and conventional pulley are held in a plate structure, which is secured to the upper elevation. The counterweight is raised and lowered from the upper elevation to the lower elevation and vice-versa by means of a guy wire which is anchored and held in relatively taught position between said upper elevation and said lower elevation.
Applicant believes that another reference corresponds to U.S. Pat. No. 4,252,214 B1 issued to Miller on Feb. 24, 1981 for a safety descent device. However, it differs from the present invention because Miller teaches a fall prevention safety device for attachment to a harness worn by a workman for providing a safely controlled descension rate from an elevated structure includes a cable having one end connected to the harness and strung around a double pulley system having an upper pulley mounted to the elevated structure and a lower pulley mounted to the upper end of a vertically reciprocal plunger which falls substantially unimpeded into a hydraulic cylinder. The cylinder substantially resists upward withdrawal of the plunger. The other cable end is connected to the upper pulley yoke such that during ascent of the workman up the structure, the lower pulley and plunger move downwardly and take up cable slack. If the workman slips and falls at any point during ascent, the cable immediately and automatically provides descension at a controlled rate determined by the resisted withdrawal rate of the plunger as the cable now pulls the lower pulley upward. The hydraulic cylinder includes a bypass line with ports communicating with the hydraulic cylinder at upper and lower compartments above and below the inner plunger end having a seal therearound defining the two compartments. The inner plunger end also carries a one-way valve, which is in an open condition during downward plunger movement and is closed by fluid pressure upon initiation of workman descent.
Applicant believes that another reference corresponds to U.S. Pat. No. 4,111,280 B1 issued to Devine, et al. on Sep. 5, 1978 for a supporting guide rail for ladder safety device. However, it differs from the present invention because Devine, et al. teach a fall prevention safety climbing device for workmen ascending and descending ladders on tall structures comprising a sleeve including a locking pawl adapted for attachment to a workman's safety belt, movable along a continuous supporting guide rail fixed to a ladder and for automatic locking engagement with the supporting rail to arrest a workman's fall. The supporting guide rail at predetermined intervals with notched sections adapts to allow disengagement in a specific safe manner of the otherwise entrapped sleeve and attached climber from the supporting guide rail. Hence, a climber can disembark at the desired platform, or level of the structure to allow another climber to pass on by to another level and thereafter reconnect himself and the attached sleeve to the supporting guide rail.
Applicant believes that another reference corresponds to U.S. Pat. No. 3,598,200 B1 issued to Thompson on Aug. 10, 1971 for an extensible safety appliance for manhole ladders. However, it differs from the present invention because Thompson teaches a sleeve attached to the rungs of a manhole ladder that has a slidable rod therein which is extendable upward from the manhole to provide a vertical railing for workman on the ladder. A support at the lower end of the rod releasably engages a ladder rung to retain the rod in extended position; when unneeded, the rod can is stored wholly within the manhole.
Applicant believes that another reference corresponds to U.S. Pat. No. 2,616,609 B1 issued to Herod on Nov. 4, 1952 for a tower ladder safety device. However, it differs from the present invention because Herod teaches a combination of a ladder equipped with a support carried by the ladder rungs, a sleeve assembly including a main part with attached housed detent and an auxiliary part connected to the main part below the latter in fixed spaced vertical relation thereto, the parts being slidably mounted on said support, the connection between the main part and auxiliary part being constructed to allow relative movement in response to curvatures in the support. The assembly includes connecting means engaged with the detent and with the auxiliary part and engaged with the safety belt of the climber to sustain the climber in the event of casual displacement of the climber from the ladder and to automatically urge the assembly upwardly with the ascent of the climber on the ladder. The tower ladder safety device also comprises a support carried by the ladder, a sleeve assembly slidably engageable with the support including a main bearing part, a substantially completely housed spring pressed detent and an auxiliary bearing part below the main bearing part and attached thereto, and means engaged with said detent and auxiliary bearing part assembly for connection to a person ascending or descending the ladder, the detent being automatically movable into locking engagement with the support in the event of displacement of the person from the ladder.
Other patents describing the closest subject matter provide for a number of more or less complicated features that fail to solve the problem in an efficient and economical way. None of these patents suggest the novel features of the present invention.